Replacing an APEX controller is often not an easy swap-out procedure. Even though there is the ability to create a backup (from the MISC tab in a local connection), that is often only ideal when reloading the same APEX after a factory reset. Even then, it often will not work when connecting many modules in a daisy chain wiring setup due to potential race conditions causing Address IDs to be unpredictably assigned. For this reason, you must connect ALL modules one by one to guarantee you have the exact same Address ID for the new APEX as now exists in the current APEX. In the case of going from an A2 Apex to an A3 APEX Pro, the built-in Fluid Monitoring module in the A3 Base Unit will guarantee to create a mismatch with IDs no matter what you do.
So below are written procedures I created for myself after going through this painful ordeal. For those with a small setup it won't be as bad, but for me it took 2 1/2 days to rebuild the same environment by hand, even with the below techniques. If you are planning an upgrade soon, read this to understand the scope of the effort so you can prepare accordingly. Realize I wrote this for my future self to read after I had forgotten everything I did. So, it's written for my setup and refers to my equipment. I left it all in there in case that can be helpful for you to create your own version. Hope this helps others. I included the original MS Word document inside a zip file so you can edit it. Good luck reefers!
So below are written procedures I created for myself after going through this painful ordeal. For those with a small setup it won't be as bad, but for me it took 2 1/2 days to rebuild the same environment by hand, even with the below techniques. If you are planning an upgrade soon, read this to understand the scope of the effort so you can prepare accordingly. Realize I wrote this for my future self to read after I had forgotten everything I did. So, it's written for my setup and refers to my equipment. I left it all in there in case that can be helpful for you to create your own version. Hope this helps others. I included the original MS Word document inside a zip file so you can edit it. Good luck reefers!